CTU in TIA will not reset — I swear the R is firing
The question
S7-1200, school cell. Counter counts. Reset coil is green. CV sits there. Lecturer said it should work. I'm on M bits because that's what the handout used. What am I overlapping?
TS ControlsThe answer
Stop using overlapping M addresses. MW3 and M3.7 live in the same bytes. CTU CV as a word will stomp the bit you think is the reset. Put the counter in an FB instance DB, or at least a dedicated DB, not merkers. Prove it with a one-rung test: count, reset, nothing else. Then add the plant conditions back until it breaks.
TS ControlsOne more thing
If you must stay in merkers, keep words on even addresses and never share the byte with a discrete. Still a bad habit. Instance data is the whole point of TIA.
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